Getting ready to install the pillars

[Rivethead]

I'm about ready to begin installing my pillars, but have a few questions first.

-Drilling Pillar holes - It will be necessary to drill the existing action holes larger to accommodate the pillars and epoxy....

What precautions/risks need to be considered against chipping the thin laminates - especially the rear hole where the sear cut is? I ordered a 7/16" forstner bit with serrated cutter- it recommends 1500 rpm for hardwood & 2500 for softwoods-my drill press can do 3100, 2340, 1720, 1100, 620 - would 1720 or 1100 be the appropriate setting? Any other drilling tips I need to know? If this bit is not a good choice, I would be willing to get another type bit.

How do you align the bit so it is both centered and perpendicular to the existing hole ? My plan is to use a 1/4" rod chucked in the press and eyeball it into place, then clamp everything down... sound about right?

Does it matter which side you drill from? Do you drill part way from each side or just plunge on thru?
The rear hole is covered by the trigger guard and the front is countersunk with a (plastic) escutcheon, so it appears to me, I can bore all the way thru on both. Any reason to stop before going all the way thru?

If drilling from the top (action side) the rear hole may have a lot of risk for bit chatter & tearout, being that half the hole is already cut out for the trigger/sear - so maybe coming in from the bottom would be safer and give the bit more side support when it reaches the thin areas - what do you think?

Another question is should I form a putty dam to keep epoxy out of the trigger/bolt handle area (basically everything behind the sear bar) but also try to get a little bedding on that small area of receiver behind the pillar?

Drilling the front hole out seems less risky, and if either end chips it can probably be repaired with epoxy.

-Pillar Length
After drilling hole, the next issue is just how long should the pillars be? That's simple - they should bridge the gap between the receiver bottom and the screw shoulder... I figure one way to get an approximate distance is to measure the action screws when seated in the receiver (also considering escutcheon or bottom metal). Of course (as I understand it) the "waterline" of the barreled action should be aligned and level with the top of the stock.

A couple of other variables may come into play determining how long the pillar needs to be. They may only account for a few thousandths difference, but should be determined beforehand to make sure the final lengths are not too long or short

Another consideration is how thick is the epoxy bed supposed to be minimum?
This will raise the action off the wood, which affects how long the pillars need to be (and the screws), everything needs to be test fit beforehand and adjusted as necessary. The bed will go in after the pillars are set, so whatever it is, the epoxy will fill the space... My question is - what is a typical thickness -should it be closer to .05" or .125" thick?

The other variable is the thickness of the stock at the screw holes. Commercial pillars are often pre-cut for specific actions. Sometimes they may need to be trimmed or even a spacer devised to maintain metal to metal contact.

I have done a bit of measuring, and it appears the factory stock and my Boyde stock are slightly different. The rear pillar looks like it's a good length, but initially my front hole seems to be significantly longer than the designated pillar.

I will have to see how the action levels up and how to deal with the plastic escutcheon, which is counter sunk further than it looks. I can't get it out without damaging the stock, so I plan on drilling thru it - It's big enough diameter that I think I can drill the bottom out and if the pillar fits flush, then I can use a washer under the screw head or if the pillar is too short, I can sink a metal spacer in to sit between the screw head and pillar. I was lucky to find a spacer of just the right size that will be below the stock - so I will have to make a some adjustment when doing the front hole.

- I made action alignment screws by cutting the heads off 2" long smooth-shank grade 5 bolts and threading the cut end, and will wax them good so they don't get stuck.
- I'm leaving my pillars flat, so at the receiver there will be spaces at the edges where epoxy will likely flow... do you fill that gap with putty or put release agent at the top contact points? How do you keep the epoxy from gluing the receiver to the pillar when installing the pillar? (it just occured to me you don't have to epoxy all the way to the top of the pillar) - just wax the tops and fill in the gaps at final bedding... yes?

Sorry I get so wordy - thanks for all your advice.

[Stumpkiller]

Make sure you dry assemble everything before bedding. I had to remove metal from the rear pillar for trigger/sear clearance. I bedded the barrel, flipped it when dry and also bedded the floor-plate. As far as thickness of the bedding: 1/8" is good. I made a LOT of clay and cardboard dams (coated with paste-wax) to make cleaning up the excess much easier. I also coated EVERYTHING not being bedded with blue masking tape, also waxed.

Dry assemble it out of the stock to judge the proper pillar height.

[Rivethead]

Great info - Thanks,
I hadn't thought of dry fitting outside the stock. Informative pics too.

[charlie b]

Forstner and brad point bits are not good for enlarging holes, IMHO. They rely on the brad point to center. If you use a mill to do this it will be 'stiff' enough to hold the bit true. The drill presses I've used are not that precise. I'd use a simple twist drill (sharp and/or new) and spin at higher speed. The MUST have is a solid stock vise on the press and a solid table to make sure the bit runs true. Go slow. Yes, start where you have enough 'meat' to center the drill.

Pillar to action can be either flat or you can grind the pillars to fit the action curvature. Doesn't seem to matter when bedding everything anyway. To keep epoxy from binding the pillar to the action you just use generous amounts of release agent on the action, stock screw and screw threads.

As you can tell there are more than one way to do this and any of them will work.

[Rivethead]

Well, I guess I always wanted a 7/16" forstner bit for something.... I saw that center point and realized there isn't anything but air for it to grab onto...
I thought for a second about plugging the hole to drill then went to the hardware store... All they had was a split point, so that's what I got - at least it looks like it will self center and is sharp - only gotta drill 2 holes.

[Robinhood]

You can square of the cutting edge of the flute so the drill doesn't "feed itself" in softer materials just grind the cutting edge of the flute inline with the drill. Otherwise it may pull in and get away from you. Works for me anyway. Learned to do that when machining aluminum and brass/bronze.

[centershot]

I only did the front pillar. By the time you cut the "notch" for the rear one, there isn't much contact surface left. I put bedding material on the rear Action screw though.

[charlie b]

You can square of the cutting edge of the flute so the drill doesn't "feed itself" in softer materials just grind the cutting edge of the flute inline with the drill. Otherwise it may pull in and get away from you. Works for me anyway. Learned to do that when machining aluminum and brass/bronze.

I used to do that with plexiglass too. Would even make it a reverse angle a little bit. High speed, slow feed.

[Dave Hoback]

Ok, quite a bit there. Let me start with aligning. Before I used a mill & had only a drill press, I would align holes to drill out larger, by first setting up with existing size bit, then switching to larger size. Of course this requires locking part down in a mill vise. (I’d recommend doing this) Just get a cheap vice if you don’t already have one. Remember, the stock must be level. Not canted side to side or front to back.

The Forstner bit will work, however, I’d recommend using a Brad Point for better drilling in wood. It can reduce tear out by first drilling the top until the Brad Point’s Pilot comes through. Then flip the stock over align with the Pilot holes & finish drilling. Also, for speed, 1100rpm will do fine.

You can build up the epoxy to strengthen the back anywhere it won’t get in the way of other components. Just fit the parts together & use your judgment. Even if there is a little too much, remember the epoxy is easy to grind away. For the bedding, you certainly don’t want .125”! Way too thick! You want the minimal amount of epoxy that does the job completely. Some people do only a skim-bed, of bed only the front Action screw. And more still skip the rear Pillar, doing just the front. There’s no incorrectprocess, only doing said process incorrectly.Research (as you are doing now), patience & care in doing will promote success.